Medusas-Mirror is a project mainly written in Java, it's free.
Bristol Game Hack game - created in only 7 hours
Medusa's Mirror!
A very simple game built at Bristol Game Hack event using Processing.
To Install & run:
Download Processing from http://processing.org/download/
Make sure you've got a reasonably recent version of Java installed. To do this go to your terminal / command prompt and type Java. If it's there you'll see the version number, if not go get it (http://www.java.com/en/download/index.jsp for English version)
Open up any of the .pde files, and press the play button.
Use wasd keys to move and aim your mirror with the mouse.